Method of decorating leather and improved decorated leather



Patented Feb. 26, 1929.

UNITE-D STATES I 1,703,675 PATENT-1 OFFICE.

\VINTHROP STANLEY LAWRENCE, OF BROOKLYN, NEW YORK, ASSIGNOR TO KAUMA-GRAPH COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

METHOD 'OF DECORATING LEATHER AND IMPROVED DECORATED LEATHER.

No Drawing.

My invention relates to a new and improved method of decorating leather,and to a new and improved decorated leather.

One of the objects of my invention is to 5 provide a method wherebyleather can be decorated in one or more colors by a direct lithographicprocess so as to produce a maximum number of color combinations at aminimum expense.

Another object of my invention is to provide a method of decoratingleather by a printing process which will permit the use of a variety ofcolor combinations and which Willprevent the ink from smearing upon thesurface of the leather.

Another object of my invention is to provide a new and improved form ofdecorated leather made according to my improved method, it beingunderstood, however that the claims herein for the new and improveddecorated leather are not limited to anypar ticular process for makingthe same.

Other objects of my invention will be set forth in the followingdescription which illustrates a preferred embodiment thereof, it

being understood that the above general statement of the objects of myinvention is intended to merely generally explain the same, and not tolimit it in any manner.

Various methods for decorating leather have been known for a great manyyears, but these methods have all been relatively expensive and they didnot permit the ready and cheap application of designs in a great manycolor combinations.

It has been proposed, for example, to apply a decorated design toleather by means of a dyeing process, but this method has been veryexpensive.

It has also been proposed to coat leather so as to provide a surfacelayer which will readily take up ink, but this method has provedimpractical for decorating leather for various purposes, as for example,in makingturn shoes because the surface film did not stretch as readilyas the moist leather, so that the surface film tended to crack and peeloff when the leather was stretched.

According to my invention a great variety of designs in a great manycolors can be simply and efliciently produced by a direct lithographicor other printing process.

My invention is particularly applicable to decorating thin skins such ascalf skins and kid skins which are afterwa ds used for mak- Applicationfiled January 26, 1927. Serial in. ieasso.

ing turn shoes, in making which it is necessary to moisten the leatherso that it can be readily stretched. According to my invention theindividual skins are caused to adhere to bases made of thin bendablecard board or paper by means of a binder or adhesive which is preferablyinsoluble in Water. F or this purpose a No. 3 and a No. 8 lithographicvarnish, mixed with a suitable cobalt dryer can be utilized. The skinscan be connected to these paper mounts or bases by means of the adhesiveand then piled up and subjected to pressure until the adhesive has setat ordinary atmospheric temperature.

This lithographic varnish mixed with the dryer is a base forlithographic inks and it can be directly handled upon a lithographicpress. Hence, the adhesive can be applied I to the paper base by meansof an ordinary lithographic press which is a decided advantage becausethe use of a lithographic press makes itpossible to apply the adhesivet6 the paper base either continuously or in separated spots or 111165.

Each skin 1s, therefore, caused to adhere to its paper mount or base ina perfectly fiat condition. Since the edges of the skins often have arounded contour because they have been taken from a portion of the bodyofrthe animal having a rounded contour, it is preferable to makeV-shaped cuts in the edges of the skins whenever this is necessary, soas to cause each skin to lie perfectly flat and tightly adhere to itsmount.

It is preferable to use an adhesive which is insoluble in water becausesome of this adhesive often creeps to the outer surface of the skin. Ifthe decorating process is applied to leather which has a water solublesurface film, then'this film flakes ofi when the leather is moistened inthe process of turning a shoe or the like, and this injures the qualityof the decoration.

Each combined mount and skin can ,now be fed to a lithographic press inthe ordinary manner, ,or be printing device.

However, in order to render decoration on the leather by a directprinting process (lithographic or otherwise) practical it is necessaryto first subject many kinds of leather to a degreasing process evenbefore the skin is connected to its mount, and it is also necessary tousecertain. special inks. This degreasing printed by any other type of Uprocess is not necessary with certain of leather, such as mocha,lambskin and other mark can be secured. On the other hand, un-

leathers commonly designated as suede.

I have discovered that unlesskid-and calf leathers are degreased by asuitable commercial process before they are printed upon, that thegreasy substances present in atanned calf skin or-kid skin form asurface layer which penetrates the lithographic ink so as to prevent itfrom properly oxidizing and setting so that the decoration tends tosmudge which, of course, would render the entire process impractical.

' Even ifsuch-skins are subjected to the ordinary degreasing processbefore they are lithographed, a certain amount-of grease always remainsin the skin.-

I have discovered thattifordinary print- I ing or lithographic inks areemployed in this process, that the grease present in such skinspenetrates the marking or decoration, or aifectsthe oxidizing of theprinting or lithographic ink in some'manner, so that the setting of theink is very much retarded. This disadvantage is cumulative because ittakes-a'certain amount of time for the greasy substances .in' the skintopenetrate or act- .upon the lithographic ink. Hence, if the printing orlithographic ink is caused to set very quickly it will be unaffected bythe greasy residues in the skin, at least to'such an extent 'thatapermanent and non-spreading less the ink is caused .to setquickly it isgradually affected by the greasy residues in the skin, so that the timeof oxidizing or setting I is very much increased and the final'markingreadily smudges.

Hence, the printing-tor lithographic ink should have a sufficientpercentage of cobalt which are ground much more fin ly Ehan has beenhitherto "customary in making lithographic inks. v l q It was"heretofore considered that carbon blackcould not be utilized asapigment in printing upon leather, by a lithographic process orotherwise, because an ink embodying carbon black spreads or smudgesquite readily when used for printing upon ordi- For example,

nary paper. It was, likewise heretofore con- 1 sideredthat thelithographic process in particular could not be successfully used inprinting upon a substance such as leather unless the leather were firstprovided with a smooth and impervious surface coating such as a lacqueror the like, because the paper which has been heretofore used inlithographic printing has had the pores thereof filled as much aspossible b means of suitable fillers, sizing, and the hike.

I have found, however, that a black lithographic ink in which carbonblack has been incorporated can be utilized for printing directly uponleather, even though the leather has not been'provided with animpervious surface film. The very fine carbon black coating and alsohave a film of adsorbed air,

[ or other dryer added thereto so as to cause it to oxidizeor set withintwenty-{four (24) hours. Thisfigure is merely approximate and is 'merelygiven by way of example bethat the ink should have a suflicient amountcause such inksare not absolutely uniform ,even thou h they-may be madeaccording to the same f ormula. c

I can, therefore, merely generally state of dryer incorporated thereinso. that it should set before .it is so softened or acted upon by thegreasy residues in the skin as to' make it impossible -.to secure a.permanent marking.

Instead linseed oil base, it is preferable to use. inks having a Chinawood oil base as these dry more quickly and give results much superiorof using inks having the ordinary than when an ink having a linseed oilbase is utilized. However, I do not wish to ex elude from my inventionthe use of a'linseed oil ink.

However, in using China wood oil inks, care must be taken not to utilizethose pi ments which have achemical action upon t e cling to or .unitevery firmly, with the de-' particles which ordinarily each have an oilygreased leather so as to provide a very clear" and permanent marking, sothatthe'action of the leather is wholly different from that of ordinarypaper in this respect.

In order to cause other plgments to unite with or adhere to the leatherso as to afford a secure and permanent marking, it is necessary to grindsuch other pigments to a much greater degree. of fineness than hashitherto been practiced, before incorporating the pigment in its oilyvehicle. For example, other pigments should be ground until about 75% ofthe particles are smaller in size than four (4) ,1., namely, .OO min. Ibelieve that these very fine particles of pigment are adsorbed to acertain extent by theleather so'as to afford a very clear and permanentmarking while coarser articles are not sufficiently adsorbed by' the lcather so that they forma marking which can be easily blurred orsmudged. Examination has shown that in printing with an ink containingcarbon black, or containing pigments which has been ground to sufficientfineness, that the carbon black or other pigment penetrates the surfaceof the leather to form a durable marking. I include letter-- press andother printing methods in my invention. That is, the ink is absorbed toa certain extent by being applied directly to the porous surface of theleather and by makmg the pigment particles substantially fine the arecarried along with the ink below the sur ace of the leather 'to acertain extent. If any of the particles of pigment remain upon or abovethe surface of the leather they are so fine that the decorative markingproduced does not smear.

4 the like.

It is not necessary that the-leather should i be connected to a mountbefore printing thereon but this is preferable as the'leather is muchmore easily manipulated. However, when the leather is connected toamount the adhesive should be properly chosen so that it should notenter the pores of the leather and stiffen it. If, for example, theleather becomes impregnated with an adhesive consisting of a drying oilsuch as linseed oil, then this oil becomes gradually oxidized so thatthe sheet of leather is stiffened. Likewise, although satisfactoryresults can be-sethe pores of the leather to stiffen 'i't. 'usinasuitable lithographic varnish having cured if the leather is connectedto the mount by a water soluble adhesive, this adhesive must be of acharacter which will not enter a su cient amount of dryer therein, thevarnish previously mentioned can be caused to set without entering thepores'of the leather so as to leave greasy spots thereon and stiffeningthe leather. If a water soluble adhesive.

such as starch is employed this mustbe used very sparingly so that itwill notventer the pores of the leather to stiffen it.

- I have described a preferred embodiment of my invention, but it isclear. that numerous chan es and omissions could be made withouteparting from its spirit.

I claim 1. A method of decorating an unfinished and commerciallydegreased leather which consists in connectin the leather to a mount bymeans of an adhesive non-soluble in water andthen applying an ink havingan oily base and a pigment directly to the exposed surface of theleather and before it is separated from its mount.

2. A method of decorating an unfinished and commercially degreasedleather which consists in connecting the leather to a mount by means ofan adhesive, causing the adhesive to set'without permitting it to enterthe pores of the leather to an extent suflicient to substantiallystiffen the leather, and then applying an ink having an oily base and a--p1gment directly to the exposed'surface of g the leather and before itis separated from its mount. a

-3. A method of decorating unfinishedleather which consists inconnecting the leather to a mount by means of an adhesive embodying adrying oil, causing the adhesive to set without permltting it to enterthe pores of the leather to an extent suflicient to substantiallystiffen theleather and then printing on the exposed surface of theleather before it is separated from its mount.

In testimony whereof I aflix my signature.

' vvnirflnor snnm umpires.

